One vertex per element, one color per generator, with an edge from x to x·s.
(10,11)(15,17)(16,18)(22,23)(25,26)(27,35)(28,30)(29,32)(31,33)(34,39)(36,37)(38,40) involution — undirected(1,2,5,4)(3,6,7,8)(9,10,14,11)(12,15,20,17)(13,16,21,18)(19,22,24,23)(25,27,31,29)(26,32,33,35)(28,38,39,36)(30,37,34,40)(2,4)(6,8)(13,21)(16,18)(19,24)(22,23)(26,33)(30,34)(32,35)(37,40) involution — undirected(3,7)(6,8)(9,11,14,10)(12,15,20,17)(13,18,21,16)(19,22,24,23)(25,28)(26,34)(27,36)(29,38)(30,33)(31,39)(32,37)(35,40)(1,3)(2,6)(4,8)(5,7)(9,12)(10,15)(11,17)(13,19)(14,20)(16,22)(18,23)(21,24)(25,29,31,27)(26,35,33,32)(28,36,39,38)(30,40,34,37)(1,4,5,2)(3,8,7,6)(9,13)(10,16)(11,18)(12,19)(14,21)(15,22)(17,23)(20,24)(25,30,31,34)(26,28,33,39)(27,37,29,40)(32,38,35,36)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.